Even some of the best behaved dogs will sometimes need a lightweight flexible basket dog muzzle. This plastic basket muzzle will fit most dogs with wide short snouts like XL Boxers, Rottweilers and Bull Mastiffs. The neck strap is leather with a metal buckle. Please measure your dogs snout! How to measure your dogs snout length & circumference. Length - measure your dog from his eyes to the tip of his nose. Circumference - measure just below the dogs eyes, go all the way around the snout. This should be the widest part of the snout just below the eyes. To get the correct size muzzle add approximately 1-1/2" to 2" to the dogs exact circumference of his snout. Here are the exact measurements of this plastic muzzle. Length on the top of the basket is 3". Length on the bottom of the basket is 4". The circumference of the basket is 16-1/2 inches. The adjustable neck strap will fit up to about a 27 inch neck. This is a plastic muzzle and will not hold up very long on a untrained aggressive dog.